Initial stage of fracture of aluminum with ideal and defect lattice

30th International Conference on Interaction of Intense Energy Fluxes with Matter

Krasnikov, V.S.^1 ; Mayer, A.E.^1

Chelyabinsk State University, Bratiev Kashirinykh Street 129, Chelyabinsk

454001, Russia^1

关键词: Defect lattices;    Initial structures;    Molecular dynamics simulations;    Negative pressures;    Nucleation rate;    Rising temperatures;    System size;    Void radius;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/653/1/012094/pdf
DOI  :  10.1088/1742-6596/653/1/012094

来源: IOP

【 摘 要 】

In this work, we investigate the initiation of fracture in an aluminum sample with the help of molecular dynamics simulations. The critical negative pressures in different simulated regions as a function of the system size and initial structure are obtained. Tension in regions with defect structures, such as initial voids or dislocations and vacancies, leads to a decrease in tensile strength. In case of initial voids, a decrease in the ratio of the void radius to the system size causes an increase in the system's tensile strength, while rising temperature causes a linear drop of tensile strength. We propose a continuum dislocation based model of nanovoids growth to describe the critical negative pressure in systems with a void. Nucleation of dislocations near a growing void is taken into account with the Arrhenius-type law for the nucleation rate.